In accordance with a rapid spread of information relevant apparatuses and communication apparatuses such as a personal computer, a video camera and a portable telephone in recent years, the development of a battery excellent as a power source thereof (such as a lithium battery) has been emphasized. The development of a lithium battery used for an electric automobile or a hybrid automobile has been advanced, for example, in the automobile industry in the field other than information relevant apparatuses and communication relevant apparatuses.
Here, organic liquid electrolyte using a flammable organic solvent is used for a conventionally commercialized lithium battery, so that the installation of a safety device for restraining temperature rise during a short circuit and the improvement in structure and material for preventing the short circuit are necessary therefor. On the contrary, with regard to an all solid battery having a liquid electrolyte replaced with a solid electrolyte, the flammable organic solvent is not used in the battery. Accordingly, it can attain the simplification of the safety device and is thereby conceived to be excellent in production cost and productivity
A method for forming a lithium complex oxide such as LiCoO2 into a film by using a physical vapor deposition (PVD) method such as a sputtering method and a vacuum deposition method has been conventionally known as a method for forming a cathode active material layer of a lithium battery (refer to Patent Literature 1 and Patent Literature 2, for example). On this occasion, it has been known that the heating of a substrate to high temperature during film format ion allows a crystallized lithium complex oxide film.